The comments came as markets continued to react violently to the uncertainty over the growing debt crisis in Greece.
"The stability of the euro is at stake. And we're determined to defend this stability as a whole," Schaeuble said following talks with International Monetary Fund chief Dominique Strauss-Kahn and European Central Bank President Jean-Claude Trichet.
Greece has said it can't pay debts coming due May 19 without euro45 billion ($59.8 billion) in bailout loans from the countries that use the euro as well as the International Monetary Fund. But Germany, which would be the biggest single contributor with some euro8.4 billion, has insisted that Greece agree to a lasting austerity plan before it will approve its share of support.
Schaeuble insisted that legislation to free up the German contribution could get through both houses of parliament within a week - as early as May 7 - if Athens wraps up its talks with the IMF and the EU quickly enough.
Strauss-Kahn and Trichet both stressed necessity for a speedy passage of the aid package for Greece.
"The faster, the better. Every day that is lost, the situation is getting worse," Strauss-Kahn said.
Trichet and Strauss-Kahn both said negotiations with the Greek government should be concluded until this weekend.
"I'm confident," Trichet said.
When asked about worries surrounding the finances of Portugal and Spain, Trichet said the euro was a stable currency, adding: "Greece is obviously a very special case."
Strauss-Kahn would not confirm reports that he had told German lawmakers Greece may need between euro100 and euro120 billion over the next three years, saying he would not comment on any figures as long as negotiations in Athens are still under way.
Schaeuble also declined to comment on the reports. He said the euro zone countries had made the decision to assist Greece in the three coming years, but only agreed on an aid package fort the first year as of now.
Strauss-Kahn also made it clear that the austerity measures will be difficult for Greece.
"It will take time. I don't want to hide it behind a rosy picture. It's not easy. It's difficult," Strauss-Kahn said.
Markets looked for reassurance from the high-level meetings in Berlin - and awaited clear word from Germany that it would come to the aid of heavily indebted Greece to keep its financial troubles from spreading to other countries.
